PURPOSE: To improve the thermal stability, ion exchange performance and oily material absorbing performance of an amorphous aluminosilicate by neutralizing the aluminosilicate until a specified pH is attained and drying it.
CONSTITUTION: An Al source such as an aq. soln. of an alkali metallic aluminate is mixed with a silica source such as an aq. soln. of an alkali metallic silicate so that the ratio of Si to Al is regulated to 0.25-6.00 and the resultant mixture is brought into a reaction at ≤50°C to prepare an amorphous aluminosilicate slurry having ≤25wt.% concn. The amorphous aluminosilicate is separated from the mother liquor and washed to remove the alkali and then a slurry of pH11.0-14.0 is prepd. by applying pressure, stirring power, etc. A neutralizing agent such as CO2 or sodium hydrogencarbonate is added to this slurry, the amorphous aluminosilicate is neutralized until ≤pH 10.5 is attained and it is dried.
FUNAKOSHI HAJIME
OZAWA TAKESHI
